What is this??

[CoryEaster23]

Found in middle chamber of tank today while doing water change. Looks like a sponge of some sort to me. Also found it on one of my zoa frags. Not sure if need to rid of it or let it be. Sorry if the picture is bad.

 

[ISpeakForTheSeas]

Looks like a sponge to me too:

Generally speaking, the only times I personally would remove a sponge are when it's killing corals or when it's spreading like a weed (and in some cases with quick spread, I might just trim it back if I like the sponge enough).

ISpeakForTheSeas said:
A very select few sponges could irritate corals due to toxins they produce (these sponges compete chemically with corals), but very few sponges seem to do this. Most sponges will happily grow along the skeleton/base of corals without bothering the corals or trying to grow over them at all (sponges generally are so harmless that even the more invasive ones can generally literally grow over the top of corals, and - as long as the coral is getting enough light still - they don't harm the corals at all even when growing over them).

So, as long as you didn't lose the sponge lottery and end up with something like Terpios hoshinota in your tank, the sponges shouldn't hurt your corals at all.

ISpeakForTheSeas said:
A lot of sponges will grow right up to and around a coral like that without causing any problems, so as long as the zoas keep opening and the sponge doesn't grow over their heads, they'll be fine.

 

[CoryEaster23]

Looks like a sponge to me too:

I can try to get better pictures tomorrow but that's all I could get at the moment. I've had sponges grow before but this looked veiny if that makes sense so it threw me off for a sec.